This invention refers to electric soldering irons; more particularly, temperature controlled soldering irons.
Temperature controlled soldering irons are not new to the electric soldering iron art. Such temperature controlled soldering irons have been found to have limited utility because of inherent inaccuracies and wide variations in tip temperature. Such inaccuracies and tip temperature variations are not acceptable in conditions where a very narrow temperature range must be maintained at the soldering tip in order to properly effect a soldered connection.
It has also been found that workers using temperature controlled soldering irons often turn the temperature control to the highest temperature setting in the mistaken belief that higher temperatures will permit faster soldering. Rather than increasing production rates, such higher temperatures either destroy the parts being soldered or produce an unacceptable soldered connection.
There is therefore a need in the art to provide a temperature controlled soldering iron having both accurate temperature control over a range of preselected temperatures and protection against on-station adjustment of the soldering iron tip temperatures to temperatures other than those prescribed for an effective soldered connections.
There is also a need in the art to be able to visually identify the tip temperature setting of temperature controlled soldering irons to a very accurate level.